#define _CRT_SECURE_NO_WARNINGS 1
#include"Stack.h"


void StackInit(Stack* ps) {
	assert(ps);
	ps->a = NULL;

	ps->capacity = ps->top = 0;
}

void StackPush(Stack* ps, STDataType data)
{
	assert(ps);
	if (ps->top == ps->capacity)
	{
		int newcapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
		STDataType* tmp = (STDataType*)realloc(ps->a, newcapacity*sizeof(STDataType));
		if (tmp == NULL)
		{
			perror("realloc");

			return;
		}
		ps->a = tmp;
		ps->capacity = newcapacity;
	}

	ps->a[ps->top++] = data;
	
}
// 出栈 
void StackPop(Stack* ps) 
{
	assert(ps);
	assert(ps->top > 0);

	ps->top--;
}
// 获取栈顶元素 
STDataType StackTop(Stack* ps)
{
	assert(ps);
	assert(ps->top > 0);

	return ps->a[ps->top - 1];
}
// 获取栈中有效元素个数 
int StackSize(Stack* ps) 
{
	assert(ps);

	return ps->top;
}
// 检测栈是否为空，如果为空返回非零结果，如果不为空返回0 
int StackEmpty(Stack* ps) 
{
	assert(ps);
	
	return ps->top == 0;
}
// 销毁栈 
void StackDestroy(Stack* ps)
{
	assert(ps);

	free(ps->a);
	ps->a = NULL;
	ps->capacity = ps->top = 0;
}